Metabolic effects of goutweed (Aegopodium podagraria L.) tincture and metformin in dexamethasone-treated rats

Abstract

Abstract: The interest in the preclinical studies of the efficacy and safety of herbal drugs combinations with antidiabetic medicines increases. Aegopodium podagraria L. (goutweed) is a plant widely used in traditional medicine. The tincture obtained from its aerial part is characterized by antihyperglycemic, lipid-lowering, hepatoprotective and nephroprotective effects and is able to partially increase the efficacy of metformin in the animals receiving dexamethasone (permissive effect in regard to glucose and lipid metabolism normalization). The objective of this study is to determine the influence of goutweed tincture combined with metformin on protein and purine metabolism as well as the state of liver in dexamethasone-treated rats. The animals were divided into 5 groups as follows: intact control, dexamethasone (untreated), dexamethasone + metformin, 50 mg/kg; dexamethasone + A. podagraria tincture, 1 ml/kg intragastrically; dexamethasone + metformin, 50 mg/kg intragastrically + A. podagraria tincture, 1 ml/kg intragastrically. Dexamethasone was used at a dose of 5 mg/kg subcutaneously for 5 days. Body weight dynamics was registered, total protein and albumin level, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase activity was determined in blood plasma, uric acid and urea content – in blood plasma and urine. Several favourable effects of the combination of goutweed tincture and metformin were seen, namely, the reduction in plasma ALT activity and increase in urea clearance as well as normalization of ALP activity. In contrast to metformin, goutweed tincture limited the dexamethasone-induced increase in plasma albumin concentration and decreased De Ritis ratio. Dexamethasone tended to increase renal uric acid excretion, metformin led to the further increment, in the groups receiving goutweed tincture this value was unchanged, but, proceeding from the normal values of uricemia, extrarenal mechanisms of the influence on purine metabolism were possible in these animals. All of the investigated preparations did not influence on plasma AST activity and caused further decrease in body weight that was reduced under the influence of dexamethasone. In-depth research of the interaction of goutweed tincture with metformin is expedient.